Technical Field
[0001] The present disclosure relates in general to an eye model. The present disclosure
relates in particular to an eye model which is recordable by means of an infrared
camera, a method for producing the eye model, and a device for using the eye model
in conjunction with an infrared camera.
Background
[0002] In a number of measurement methods for measuring the eye, electromagnetic radiation
(hereinafter "light" for short) is radiated onto and/or into the eye to be examined,
and the radiation reflected from the eye is detected and evaluated. Thus, for example,
in the field of refractive laser treatment of the human eye, eye tracking systems
(so-called eye trackers) having at least one infrared camera are used for recording
infrared light reflected from the eye and determining a position and an orientation
of the eye based on the recorded infrared images. By use of suitable processing software,
a movement of the eye in the course of treatment may thus be detected and quantified.
[0003] The determination of the position and the orientation of the eye by means of the
eye tracker is based on the detection of eye structures, such as the eye pupil, the
iris structure, the limbus, and blood vessels within the sclera, within the recorded
infrared images or VIS images. Test objects for use in test measurements (during calibration,
for example) of the eye tracker therefore also have such eye structures. The test
objects are customarily present as sheet- or plate-shaped objects having an imprinted
replica of one or more of the eye structures (for example, only the eye pupil).
[0004] For example, a lateral translation of an eye may be simulated and tracked by means
of the eye tracker by effecting a two-dimensional relative movement between the eye
tracker and the test object. However, it should be noted that the eye (for example,
during the refractive laser treatment) may also undergo translations along the optical
axis of the eye, and rotations about the optical axis and also about spatial axes
extending perpendicularly thereto. Eye trackers nowadays are configured for detecting
the described movements. However, within the scope of test measurements it is not
possible to adequately simulate all degrees of freedom of the eye movement by means
of the sheet- or plate-shaped test objects.
[0005] Reference is made to
US2013030524 and
US2014170623 cited as relating to the state of the art.
US2013030524, for example, relates to providing an artificial lens for use in an artificial eye
device for cataract surgery practice. The artificial lens includes an artificial nucleus
corresponding to a human eye lens nucleus and an artificial cortex corresponding to
a human eye lens cortex.
WO2005/047938 relates to a method for determining torsional misalignment including calculating
the accuracy of a cyclotorsional algorithm by comparing a known torsional misalignment
angle between a test device in two images to a calculated torsional misalignment angle
Summary
[0006] It will be appreciated that the scope of the invention is in accordance with the
claims. Accordingly, there is provided a device in accordance with claim 1. Further
features are provided in accordance with the dependent claims. The specification also
includes arrangements outside the scope of the claims provided as background and to
assist in understanding the invention.
Brief Description of the Drawings
[0007] Supplemental features, advantages, and components of the present invention are apparent
from the following description of the appended drawings, which show the following:
- Figures 1A to 1D
- show one exemplary embodiment of an eye model;
- Figures 2A and 2B
- show one exemplary embodiment of a blank for producing the eye model; and
- Figure 3
- shows a device for using the eye model.
Detailed Description of the Exemplary Embodiments
[0008] Figures 1A to 1D show schematic illustrations of one exemplary embodiment of an eye
model, denoted in general by reference numeral 10. Figure 1A shows a perspective view,
Figure 1B shows a top view, Figure 1C shows a side view, and Figure 1D shows a sectional
view of the eye model 10 along a section line I indicated in Figure 1B.
[0009] In the exemplary embodiment shown in Figures 1A to 1D, the eye model 10 is formed
from an eye body 12. The eye body 12 has a first flattened area 14 within which the
surface of the eye body 12 is planar. The first flattened area 14 forms a disk-shaped
(for example, ellipsoidal and in particular circular) cover surface of the eye model
10. A convexly curved peripheral surface 18 which circumferentially surrounds the
cover surface 14 in a ring-like manner is joined to the cover surface 14 via a first
ring-shaped edge 16. The peripheral surface 18 is designed as an annular surface which
is in accordance with (or which conforms to) the shape of an ellipsoidal surface (for
example, a spherical surface).
[0010] The eye body 12 also has a second flattened area 20 opposite from the cover surface
14. The second flattened area 20 forms a disk-shaped (for example, ellipsoidal and
in particular circular) base area of the eye model 10. It may be provided that the
base area 20 (via a ring-shaped edge) adjoins the annular surface 18. In the exemplary
embodiment shown in Figures 1A to 1D, however, the eye body 12 has a lateral surface
22 which extends between the annular surface 18 and the base area 20. The planar lateral
surface 22 describes the shape of a cylindrical surface which adjoins the base area
20 and the annular surface 18, respectively, via two circular edges 24, 26 having
the same circumference. In another exemplary embodiment, the lateral surface 22 may
have a design which conforms to a conical surface, for example.
[0011] The eye model 10 shown in Figures 1A to 1D includes a simulation (i.e., replica)
of a human sclera. The sclera simulation is formed by the eye body 12, in particular
the portion of the eye body 12 that is bordered by the annular surface 18. The eye
body 12 is made of white polyvinyl chloride. No significant diffuse reflection takes
place within the polyvinyl chloride when the eye body 12 is illuminated with infrared
light. The eye body 12 thus appears white, even under infrared illumination.
[0012] In another exemplary embodiment, it may be provided that instead of being made of
white polyvinyl chloride, the eye body 12 is made of a bright, in particular white,
plastic material containing (for example, white) polyvinyl chloride at least as the
main component. The plastic material may include further components, such as plasticizers
or additional plastics. In any case, the plastic material should be designed in such
a way that it appears bright, in particular white, even under infrared illumination.
[0013] For the eye model 10 shown in Figures 1A to 1D, the simulation includes only a portion
of the human sclera. The portion of the eye body 12 having the sclera simulation forms
the shape of an ellipsoidal layer (for example, a spherical layer). Alternatively,
it may be provided to enlarge the simulated portion of the sclera to form a simulation
of essentially the entire sclera. In the latter case, the eye body 12 may assume the
shape of an ellipsoidal dome (for example, a spherical dome).
[0014] As is apparent in Figures 1A and 1B, a pattern 28 is applied to the cover surface
14 of the eye model 10. The pattern 28 includes the simulation of an eye pupil 30
and of an iris structure 32. The pattern 28 extends over the entire flattened area
of the eye body 12 which forms the cover surface 14 of the eye model 10. In another
exemplary embodiment, it may be provided that the pattern 28 simulates only the iris
structure 32 or only the eye pupil 30. At least in this case, it is possible to apply
no pattern 28 to an area of the cover surface 14 of the eye model 10 (for example,
in the case of only a pupil replica, in an area around the eye pupil 30).
[0015] It may also be provided that a portion of the pattern 28 (for example, the simulation
of the iris structure 32) extends in a convexly curved surface area of the eye body
12 or is applied entirely in a convexly curved surface area of the eye body 12 (for
example, conforming to the shape of the annular surface 18). In the latter case, it
may be provided that only the simulation replica of the eye pupil 30 is situated on
the cover surface 14 of the eye model 10.
[0016] As is apparent in Figures 1A and 1B, the simulation of the eye pupil 30 and the simulation
of the iris structure 32 contrast in color with the sclera simulation. The simulation
of the eye pupil 30 and of the iris structure 32 may be implemented in gray tones,
in colors of the RGB color space, or in colors of the CMYK color space.
[0017] At least in the exemplary embodiment shown in Figures 1B and 1C, the flattened area
of the eye body 12 having the pattern 28 is designed as a circular disk. The flattened
area (and thus the pattern 28) has a diameter ∅
D of about 12 mm. Alternatively, in another exemplary embodiment the diameter ∅
D may have values which differ from 12 mm, in a range from about 9 mm to about 14 mm
(in particular between about 10 mm and about 13 mm). The diameter ∅
D of the flattened area having the pattern 28 corresponds to a typical diameter of
an outer edge of a human iris.
[0018] In addition, the flattened area which forms the base area 20 of the eye model 10
is present as a circular disk. A diameter ∅
G of the base area 20 is about 24 mm, at least in the exemplary embodiment shown in
Figures 1B and 1C. Furthermore, the eye body 12 has a height h
U, extending perpendicularly with respect to the base area 20 of the eye model 10 in
the area of the annular surface 18, of about 7.8 mm. A height h
M of the eye body 12, extending perpendicularly with respect to the base area 20 in
the area of the lateral surface 22, is about 2.2 mm.
[0019] In another exemplary embodiment, at least one of the values of the diameter ∅
G and of the heights h
U, h
M of the eye body 12 may differ from the stated values. Thus, in the case of the simulation
of a smaller or larger portion of the human sclera, it may be provided that the diameter
∅
G and the height h
U vary as a function of one another.
[0020] As is clear in Figure 1D, in the region of the flattened area the eye body 12 is
provided with a recess 30 on the side of the annular surface 18 opposite from the
pattern 28. Specifically, the recess 30 is a threaded hole which is introduced into
the base area 20 of the eye model 10. The threaded hole 30 may be used, for example,
to arrange (to screw, for example) the eye model 10 to a positioning device (not shown).
[0021] In the exemplary embodiment shown in Figure 1D, the threaded hole 30 extends into
the eye body 12, starting from an area in the middle of the base area 20 of the eye
model 10. The threaded hole 30 also has a height h
A, extending perpendicularly with respect to the base area 20, of about 6.5 mm. In
another exemplary embodiment, it may be provided that a plurality of recesses (for
example, a plurality of threaded holes 30) is provided within the eye body 12. In
addition, the recess or recesses may have an extension that is different from the
extension as described with regard to the exemplary embodiment shown in Figure 1D.
[0022] Figures 2A and 2B show schematic illustrations of one exemplary embodiment of a blank,
denoted in general by reference numeral 40, made of the plastic material that is used
for producing the eye body 12 (as described with reference to the preceding figures).
Figure 2A shows a perspective view, and Figure 2B shows a side view, of the blank
40 (oriented in the direction of the arrow shown in dashed lines in Figure 2A).
[0023] The plate-shaped blank 40 of the plastic material (in this case, white polyvinyl
chloride) has two planar, oppositely situated blank flat sides 42, 44. A plurality
of patterns 28 (see Figures 1A and 1B) is applied to a first of the blank flat sides
42 (a blank top side 42).
[0024] For producing the eye model 10 shown in the preceding figures, an eye body 12 or
a plurality of eye bodies 12 is separated from the blank 40 (as marked by dashed lines
in Figure 2B). In the process, a side surface which joins the flattened areas of the
eye body 12 is respectively produced in the blank 40. The cover surface 14 and the
base area 20 of the eye model 10 are formed by the separated sections of the blank
flat sides 42, 44. In the exemplary embodiment shown in Figure 2B, a height h
R which extends between the blank flat sides 42, 44 thus corresponds to a height of
the eye model 10 which extends between the flattened areas of the eye body 12 (see
Figure 1C).
[0025] The plurality of the eye bodies 12 separated from the blank 40, i.e., the plurality
of produced eye models 10, preferably corresponds to the plurality of the patterns
28 applied to (i.e., formed on) the blank 40. According to the exemplary embodiment
of the blank 40 shown in Figure 2A, the patterns 28 are already applied to the blank
top side 42 before the eye body 12 is separated. For separating the eye body 12, the
convexly curved peripheral surface 18 which surrounds the pattern 28 in a ring-like
manner is produced in the blank 40. In addition, in the exemplary embodiment shown
in Figure 2B, the lateral surface 22 which adjoins the peripheral surface 18 is produced
in the blank 40.
[0026] Applying the patterns 28 prior to the separation step simplifies and speeds up the
production of the eye models 10 compared to individually applying a pattern 28 to
a respective eye body 12 which has already been separated. In another exemplary embodiment,
it may still be provided to apply an individual pattern 28 or a plurality of patterns
28 (on a planar and/or a convexly curved area of the surface) after the eye body 12
or the plurality of eye bodies 12 has been separated. The plurality of patterns 28
may substantially resemble each other. At least in this case, the applying of the
plurality of patterns 28 to the eye bodies 12 or to the blank 40 may be carried out
on an automated basis.
[0027] The pattern 28 is preferably imprinted on the blank 40 or the eye body 12 which has
already been separated from the blank 40. Alternatively, the pattern 28 may be formed
in some other way on the blank 40 or the eye body 12 which has already been separated
from the blank 40. Thus, for example, it may be provided to paint on the pattern 28,
or to apply an adhesive element which bears the pattern 28. It may be further provided
to apply another pattern, such as a simulation of blood vessels, to the portion of
the eye body 12 having the sclera simulation (as described with regard to Figs. 1A
to 1D).
[0028] In another exemplary embodiment, it may also be provided that only a single eye body
12 is separated from the blank 40 in order to produce a single eye model 10. At least
in this case, the blank 40 may also be rectangular shaped, for example.
[0029] It is provided to mill out the eye bodies 12 from the blank 40 shown in Figures 2A
and 2B. Alternatively or additionally, the separation of the eye bodies 12 (or of
a single eye body 12) may include some other cutting or chipping machining of the
blank 40. It is also provided that the eye bodies 12 are separated from the blank
40 in chronological succession. However, the plurality of eye bodies 12 may also be
separated partially simultaneously (for example, simultaneously in pairs) or simultaneously.
[0030] The production of the eye model 10 may include further steps. Thus, it is provided
to introduce the threaded hole 30 shown in Figure 1D (or a plurality of threaded holes
30) into the blank 40 in association with each eye body 12 to be separated from the
blank 40. Specifically, the threaded hole 30 is introduced into the blank 40 (for
example, by milling out plastic material), starting from the second blank flat side
44 situated opposite from the blank top side 42. Alternatively, the threaded hole
30 may also be introduced into the eye body 12 after the eye body 12 is separated,
starting from the base area 20 of the eye body.
[0031] In an alternative embodiment, at least some of the steps of producing the eye model
10 may be replaced by 3D printing. For example, the eye body 12 may be 3D printed
with the plastic material (such as white polyvinyl chloride). In this case, the 3D
printing may further include the step of applying the pattern 28 to the eye body 12
by printing colored plastic material (such as colored polyvinyl chloride).
[0032] Figure 3 shows, in a highly schematic block diagram, one exemplary embodiment of
a device, denoted in general by reference numeral 50, for using the eye model 10 described
with reference to Figures 1A to 2B.
[0033] The device 50 includes an eye tracking system 52 and a laser device 53 for refractive
laser treatment of a human eye. The eye tracking system 52 may be an eye tracker which
is designed for detecting and quantifying a translational and a rotational eye movement
in multiple dimensions, in particular in more than two dimensions. The eye tracker
52 may, for example, be part of the laser device 53, illustrated in a highly schematic
manner.
[0034] The eye tracker 52 may be implemented in various ways known to those skilled in the
art. In the exemplary embodiment shown in Figure 3, the eye tracker 52 includes an
infrared camera unit 54 and a processing unit 56. The eye tracker 52 further includes
means (not shown here) for obtaining information related to the direction along the
optical axis of the human eye or the eye model 10, such as information on a movement
of the eye or the eye model 10 along the optical axis. The means may, for example,
include a stripe projector located in the field of view of the infrared camera unit
54.
[0035] The infrared camera unit 54 is configured for recording a plurality of infrared images
of the eye model 10 (and the stripe projector), for example by means of one or a plurality
of infrared cameras positioned around the eye model 10. It is provided that such an
infrared image of the eye model 10 contains the pattern 28 and at least one portion
of the sclera simulation which adjoins the pattern 28 (i.e., an area of the annular
surface 18 of the eye body 12). On account of the plastic material described with
reference to Figures 1A to 2B, the sclera simulation appears bright, even under infrared
illumination by the infrared camera unit 54. Thus, the pattern 28 contrasts in color
with the bright sclera simulation, even under infrared illumination, i.e., in the
infrared image.
[0036] The processing unit 56 is configured for determining a position of the center of
the simulation of the eye pupil 30 and an orientation of the simulation of the iris
structure 32 (see Figures 1A, 1B, and 2A) relative to the eye tracker 52 from a single
infrared image and a plurality of infrared images of the eye model 10. Depending on
the design of the pattern 28, in another exemplary embodiment it may be provided,
for example, that the processing unit 56 determines only the position of the center
of the simulation of the eye pupil 30, for example by recognizing the pupil margin.
[0037] In the exemplary embodiment shown in Figure 3, the eye tracker 52 or the processing
unit 56 is connected to a control system 58 of the laser device 53 via a suitable
interface, so that the data concerning the movement of the eye model 10 collected
by the eye tracker 52 may be relayed to the control system 58 in order to carry out
the control of laser radiation generated by the laser device 53, taking into account
the eye position and eye orientation determined by the eye tracker 53. The beam path
of the laser radiation is indicated by the arrow denoted by reference numeral 60.
[0038] In the exemplary embodiment shown in Figure 3, the device 50 also includes a positioning
device 62 on which the eye model 10 is arranged. The eye model 10 may thus be fixed,
for example, by screwing the eye model 10 onto threaded sections (screws, for example),
not shown, of the positioning device 62. It is provided to situate the positioning
device 62, together with the eye model 10 arranged thereon, in the area of a head
support of a patient table (not illustrated here), for example by inserting into the
patient table by means of a simple form-locked fit.
[0039] The positioning device 62 is also designed to mechanically adjust the position and
orientation of the eye model 10. A relative movement between the eye model 10 and
the eye tracker 52 is thus effected. Alternatively or additionally, in another exemplary
embodiment the relative movement between the eye tracker 52 and the eye model 10 may
take place by changing the position and orientation of the eye tracker 52.
[0040] As the result of such a relative movement between the eye model 10 and the eye tracker
52, the three-dimensional sclera simulation (as described with reference to Figures
1A to 2B) allows the simulation of a translational movement of a human eye along and
perpendicular to the optical axis, and also of a rotational movement of the eye about
the optical axis (eye roll about the z-axis) and the spatial axes perpendicular thereto
(eye roll about the x-axis and the y-axis). The effected relative movement may be
detected and quantified during the movement by repeated infrared image recording and
infrared image processing by means of the eye tracker 52. Thus, the functionality
of the eye tracker 52 may be tested, for example calibrated, for all degrees of freedom
of eye movements (as they occur, for example, during a refractive laser treatment).
[0041] When the eye model 10 is used in conjunction with the device shown in Figure 3, based
on simulated movements of the eye model 10, such as effected by the positioning device
62, one or more function tests of the laser device 53 may also be carried out, and/or
the laser device 53 may be calibrated, and/or a laser treatment of a human eye by
means of the laser device 53 with simultaneous eye tracking may be simulated.
1. A device (50) for calibrating an eye tracker (52), the device (50)comprising:
an eye model (10) comprising an eye body (12) having:
a sclera simulation which is made of a bright plastic material, the plastic material
containing a polyvinyl chloride at least as the main component, the sclera simulation
forming an annular surface in accordance with the shape of a spherical or ellipsoidal
surface;
a pattern (28) which contrasts in color with the sclera simulation, the pattern simulating
an eye pupil (30) and an iris structure (32), the eye body (12) having a first flattened
area (14) on which the pattern (28), is situated; and
a second flattened area (20) on the side of the annular surface opposite from the
pattern (28), the region of the second flattened area provided with a threaded hole
(30);
an eye tracker (52) comprising an infrared camera (54);
a positioning device (62) configured to:
fasten the eye model (10) at the threaded hole; and
mechanically adjust the position and orientation of the eye model (10) relative to
the infrared camera (54) while images of the eye model (10) are recorded; and
provide a simulation of a rotational movement of the eye about an optical axis thereof,
rotational movement of the eye about spatial axes perpendicular thereto, and translational
movement of the eye along and perpendicular to the optical axis, by adjustment of
the position and orientation of the eye model relative to the eye tracker (52);
the eye tracker configured to track movement of the eye model, the movement of the
eye model being detected and quantified during the movement thereof by repeated infrared
image recording and processing by means of the eye tracker (52).
2. The device according to Claim 1, wherein the plastic material is white in the area
of the sclera simulation.
3. The device according to Claim 1, wherein the transition from the annular surface to
the flattened area is formed by a ring-shaped edge (16).
4. The device according to one of Claims 1 to 3, wherein the pattern is formed by imprinting
or painting of the eye body, or by adhering to the eye body an adhesive element which
bears the pattern.
5. The device according to one of Claims 1 to 4, wherein the surface of the eye body
in the area of the sclera simulation forms a convexly curved annular surface.
1. Vorrichtung (50) zum Kalibrieren eines Eye Trackers (52), wobei die Vorrichtung (50)
umfasst:
ein Augenmodell (10), das einen Augenkörper (12) umfasst, mit
einer Sklerasimulation, die aus einem hellen Kunststoffmaterial gefertigt ist, wobei
das Kunststoffmaterial ein Polyvinylchlorid mindestens als Hauptkomponente enthält,
wobei die Sklerasimulation eine ringförmige Oberfläche gemäß der Formgebung einer
sphärischen oder ellipsoidalen Oberfläche bildet;
einem Muster (28), das farblich mit der Sklerasimulation kontrastiert, wobei das Muster
eine Augenpupille (30) und eine Irisstruktur (32) simuliert, wobei der Augenkörper
(12) einen ersten abgeflachten Bereich (14) aufweist, auf dem sich das Muster (28)
befindet; und
einem zweiten abgeflachten Bereich (20) auf der Seite der ringförmigen Oberfläche
gegenüber von dem Muster (28), wobei die Region des zweiten abgeflachten Bereichs
mit einem Gewindeloch (30) ausgestattet ist;
einen Eye Tracker (52), der eine Infrarotkamera (54) umfasst;
eine Positioniervorrichtung (62), die ausgestaltet ist zum:
Befestigen des Augenmodells (10) an dem Gewindeloch; und
mechanischen Anpassen der Position und Orientierung des Augenmodells (10) relativ
zu der Infrarotkamera (54), während Bilder des Augenmodells (10) aufgezeichnet werden;
und
Bereitstellen einer Simulation einer Rotationsbewegung des Auges um eine optische
Achse davon, Rotationsbewegung des Auges um dazu senkrechte räumliche Achsen, und
Translationsbewegung des Auges entlang und senkrecht zu der optischen Achse durch
Anpassung der Position und Orientierung des Augenmodells relativ zu dem Eye Tracker
(52);
wobei der Eye Tracker ausgestaltet ist, um Bewegung des Augenmodells zu verfolgen
(zu tracken), wobei die Bewegung des Augenmodells während dessen Bewegung durch wiederholte
Infrarotbildaufzeichnung und Verarbeitung mittels des Eye Trackers (52) detektiert
und quantifiziert wird.
2. Vorrichtung nach Anspruch 1, wobei das Kunststoffmaterial im Bereich der Sklerasimulation
weiß ist.
3. Vorrichtung nach Anspruch 1, wobei der Übergang von der ringförmigen Oberfläche zu
dem abgeflachten Bereich durch einen ringförmigen Rand (16) gebildet wird.
4. Vorrichtung nach einem der Ansprüche 1 bis 3, wobei das Muster durch Bedrucken oder
Malen des Augenkörpers oder durch Kleben eines Klebeelements, welches das Muster trägt,
an den Augenkörper gebildet wird.
5. Vorrichtung nach einem der Ansprüche 1 bis 4, wobei die Oberfläche des Augenkörpers
im Bereich der Sklerasimulation eine konvex gekrümmte ringförmige Oberfläche bildet.
1. Dispositif (50) pour calibrer un système de suivi oculaire (52), le dispositif (50)
comprenant :
un modèle d'œil (10) comprenant un globe oculaire (12) ayant :
une simulation de la sclérotique qui est constituée d'une matière plastique brillante,
la matière plastique contenant au moins du chlorure de polyvinyle comme composant
principal, la simulation de la sclérotique formant une surface annulaire conforme
à la forme d'une surface sphérique ou ellipsoïdale ;
un motif (28) dont la couleur contraste avec la simulation de la sclérotique, le motif
simulant une pupille d'œil (30) et une structure d'iris (32), le globe oculaire (12)
ayant une première zone aplatie (14) sur laquelle se trouve le motif (28) ; et
une seconde zone aplatie (20) sur le côté de la surface annulaire opposé au motif
(28), la région de la seconde zone aplatie étant pourvue d'un trou fileté (30) ;
un système de suivi oculaire (52) comprenant une caméra infrarouge (54) ;
un dispositif de positionnement (62) configuré pour :
fixer le modèle d'œil (10) au niveau du trou fileté ; et
ajuster mécaniquement la position et l'orientation du modèle d'œil (10) par rapport
à la caméra infrarouge (54) pendant que les images du modèle d'œil (10) sont enregistrées
; et
fournir une simulation d'un mouvement de rotation de l'œil autour de son axe optique,
d'un mouvement de rotation de l'œil autour d'axes spatiaux perpendiculaires à celui-ci,
et d'un mouvement de translation de l'œil le long et perpendiculairement à l'axe optique,
par ajustement de la position et de l'orientation du modèle d'œil par rapport au système
de suivi oculaire (52) ;
le système de suivi oculaire étant configuré pour suivre le mouvement du modèle d'œil,
le mouvement du modèle d'œil étant détecté et quantifié au cours de son déplacement
par l'enregistrement et le traitement répétés d'images infrarouges au moyen du système
de suivi oculaire (52).
2. Dispositif selon la revendication 1, dans lequel le matériau plastique est blanc dans
la zone de simulation de la sclérotique.
3. Dispositif selon la revendication 1, dans lequel la transition entre la surface annulaire
et la zone aplatie est formée par un bord en forme d'anneau (16).
4. Dispositif selon l'une des revendications 1 à 3, dans lequel le motif est formé par
impression ou peinture du globe oculaire, ou par adhésion au globe oculaire d'un élément
adhésif qui porte le motif.
5. Dispositif selon l'une des revendications 1 à 4, dans lequel la surface du globe oculaire
dans la zone de simulation de la sclérotique forme une surface annulaire convexe.